1. Field of the Invention
The invention relates to an integrated module having a first and a second integrated circuit which are arranged on separate substrates. The invention furthermore relates to a tester system for testing such an integrated module and to a method for driving a first and a second output terminal of such an integrated module.
2. Description of the Related Art
In order to provide powerful modules, more than one substrate (die) having an integrated circuit may be inserted into a housing and may be connected to external terminals of the module using common or mutually separate bonding wires and the like. The substrates having the integrated circuits are usually stacked and inserted into such a module. In this case, the terminals of the individual integrated circuits are connected to one another and to an external terminal in accordance with their function.
To drive the individual integrated circuits separately, some of the terminals are not connected to one another and are routed directly to individual mutually separate output terminals. The individual integrated circuits are assembled and installed in the finished module after the wafer test and maybe even after the circuits have been repaired. After assembly, however, the module's operation must be tested again.
Such modules having a plurality of individual integrated circuits have hitherto been tested in the same way as a module having only one integrated circuit. That is to say, in the case of memory circuits, two 256 megabit circuits, for example, are treated and tested like one 512 megabit module. The test time required thus corresponds approximately to the test time of a 512 megabit memory circuit.